A structural crack, a roof letting water in, foundations on the move: the decennial guarantee runs for ten years from acceptance of the works, and whether it applies turns on how the defect is characterised. Maître Léa Scemama, a member of the Paris Bar, characterises the defect, calls on the damage insurance and brings proceedings against the builders and their insurers.
What the decennial guarantee actually covers
Established by the Spinetta Act of 4 January 1978 and codified in article 1792 of the Civil Code, the decennial guarantee covers, for ten years from the acceptance of the works, damage that compromises the soundness of the building or makes it unfit for its purpose. Subsiding foundations, structural cracks, a defective roof or infiltrations that make the premises uninhabitable all fall within its scope.
Strict liability
You do not have to prove any fault. Liability rests automatically on the builder, who can only escape it by proving an external cause: force majeure, the act of a third party or your own fault. This presumption shifts the balance of power in favour of the party suffering the defect.
A reversal of case law occurred on 21 March 2024 (Court of Cassation, Third Civil Chamber, appeal no. 22-18.694): an item of equipment installed on an existing structure, such as a heat pump, a boiler or photovoltaic panels, falls under the decennial guarantee only if it constitutes a work in its own right. Otherwise, the resulting defects fall under ordinary contractual liability. This distinction governs the strategy and the time limit to act.
Related guarantees not to be confused
Three regimes coexist, and confusing them means losing rights. The one-year completion guarantee covers all defects reported at acceptance or within the following year. The two-year guarantee of proper functioning covers removable equipment, such as a roller shutter. Finally, the decennial guarantee covers serious damage for ten years.
| Guarantee | Duration | What it covers |
|---|---|---|
| Completion guarantee | 1 year | All defects reported at acceptance or within the following year |
| Guarantee of proper functioning | 2 years | Removable items of equipment, such as a roller shutter |
| Decennial guarantee | 10 years | Serious damage to the works: soundness compromised or unfit for their purpose |
Damage insurance, your best ally
Since 1978, any project owner who commissions construction must take out damage insurance before the works begin. Many individuals overlook it. That is a costly mistake. This insurance pre-finances repairs without waiting for a court to identify the party at fault: you are compensated, then the insurer pursues the claims in your place. The time saved is often counted in years.
The damage insurer is bound by strict deadlines: after receiving the claim, it has sixty days to notify its decision on the principle of cover, then, if accepted, ninety days to make an offer of compensation (article L242-1 of the Insurance Code). Once these deadlines pass, the insured may incur the necessary expenditure and the sums due are increased.
What to do when a defect appears
Report the loss to the damage insurer without delay, by registered letter. Keep everything: dated photographs, letters, the acceptance report. Except in an emergency, do not start repairs before an expert assessment has established the cause. If the insurer disputes the claim, a judicial expert assessment may be ordered on an interim basis under article 145 of the Code of Civil Procedure. Everything flows from acceptance, which sets the starting point of the ten years.
In the absence of a formal report, article 1792-6 of the Civil Code provides for acceptance by agreement or, failing that, by the court, pronounced in every case on an adversarial basis (Cass. 3e civ., 20 October 2021, no. 20-20.428). Tacit acceptance does not appear in the text: it is a construction of case law, admitted where the owner unequivocally shows an intention to accept the works, which taking possession together with payment of the works allows to be presumed. This is decisive: without acceptance, the decennial guarantee cannot apply.
A defect may fall under several regimes depending on its nature. Our page on construction defects explains how to match each defect to the right guarantee. Depending on the framework, the works may also fall under a new-build house contract or a works contract. Our real estate law hub presents all our services.
Frequently asked questions
Does the decennial guarantee cover cracks?
It depends on their seriousness. Cracks that reveal a structural problem or let water through fall under the decennial guarantee. Purely cosmetic microcracks, with no impact on soundness or use, are excluded.
When do the ten years start running?
From the acceptance of the works, whether pronounced with or without reservations.
Do I have to wait for a trial to be compensated?
No, if you have taken out damage insurance. It pre-finances the repair works and then pursues the claims in your place.